Mike Johnson had soldiered through 12 marathons in 12 months. The yearlong challenge was a personal one, with an added goal of raising money for a Bible camp in Amery, Wis.

Boston was to be his mountaintop, yet it’s the one he and thousands of others would not reach.

Johnson was spent heading into the marathon, but Hopkinton’s start-line vibe temporarily rejuvenated him. The chilly but gorgeous morning, the twitchy pre-race energy and banter with strangers, the festive atmosphere. “I was not all that excited to be running, but was excited to be in this event. It was big.”

Just past the 25-mile mark, on Commonwealth Avenue, Johnson scanned the horizon and saw runners stopped mid-run. Spectators told him of explosions, but details were scant. Meanwhile, more runners converged on the bottleneck. Some decided to get off their feet and were lying on the street.

Johnson borrowed a spectator’s phone and recalled having the good fortune to reach his wife, Zanny, back in Stillwater. “I just said, ‘I want to let you know something is going on. I’m safe.’ ”

Action beyond the barriers was intense, too, a torrent of police cars, ambulances and black SUVs. After 30 minutes or so, he knew there would be no victory lap down Boylston Street. “I thought, this is not just a stop in the race. This race is over.”

With that, Johnson climbed over a spectator barrier and started walking back to a friend’s hotel, where they found one another in a busy lobby.

‘People are excited’

Johnson, one of 5,633 runners who couldn’t finish because of the bombs, said he is grateful for another chance to take his place in Boston Marathon history. Support has been a big motivator. “People are excited for me.”

“Once I qualified for Boston [last year], then I felt like, I am a marathoner,” Johnson said. “So to go back, to be able to run again on that course, with those people, is a big deal for me.”